1. Field of the Invention
The present invention relates to an off-line teaching apparatus which is used when a robot model displayed on a monitor is operated by using a keyboard and/or a pointing device (for example, a mouse) and which makes it possible to optimally express the action in conformity with a display form of the robot model.
2. Description of the Related Art
Recently, in order to apply a robot to a variety of workings, in general, a variety of tools are attached to a face plate of a robot arm to allow the robot to perform the workings.
The programming for the robot includes the on-line programming (on-line teaching) and the off-line programming (off-line teaching). In the case of the on-line teaching, the arm of the robot is moved to pass through necessary points or along a locus by using a push button, an operation button, an operation handle, and a joystick so that the control unit is allowed to store the points or the locus. When the robot is operated at the driving stage, the robot reproduces and executes the stored movement.
In the off-line teaching, the operation procedure is programmed without directly using the robot. In the case of the off-line teaching, the software is programmed such that the movement of each joint is calculated in order to move the end effector to a necessary position in a necessary direction.
The movement of the robot can be displayed in animation on a graphic terminal connected to a computer, by adding a graphic function to the system which is used to execute the off-line teaching. The off-line teaching based on the use of the graphic has the following advantages.
(1) When the operation program is debugged by using the graphic, it is possible to reduce the time and the labor as compared with a case in which an actual robot is used.
(2) It is possible for the user to begin programming before the robot is introduced. Further, various types of robots can be tested on the monitor screen to select a type of machine which is most suitable for the plan.
(3) It is possible to avoid confliction in view of surrounding situations when the movement of the robot is simulated.
(4) It is possible to use a common database of CAD/CAM. For example, when a computer for CAD/CAM stores a body shape of an automobile, the designer can designate the place to be subjected to spot welding.
In the off-line teaching system having the graphic function, a robot model is displayed on a monitor screen, and the robot model is allowed to act in accordance with an operation command given by the operator.
In such a system, it takes a long time to process the program which is executed to display the robot model in animation. Therefore, the operation command, which is inputted by the operator one after another, cannot be processed in real time. It is assumed, for example, that a pointing device such as a mouse is operated in order to move the robot model. When the load is small, then the system usually makes a sensitive response to the movement of the pointing device, and the robot model on the screen is also moved in accordance with the amount of operation of the pointing device. However, when the robot model has a complicated structure, and it is constructed by a variety of drawing lines, then the capacity of display data is large. Therefore, it is impossible to make the sensitive response to the movement of the pointing device, and a considerably delay occurs in the response.
In such a case, the operator misunderstands that the operation command is not inputted into the system. As a result, the operator inputs the same operation command a number of times. Therefore, an inconvenience arises in that it is necessary to wait for the processing performed by the system to that extend (in a degree corresponding to the vain input).
In the conventional technique, the amount of action of the robot model, which is given in response to the amount of operation of the pointing device, is constant for the case in which the robot model is displayed with magnification and for the case in which the robot model is displayed with reduction. The display with magnification is made in accordance with a request that the robot model is allowed to make fine movement. However, actually, the robot model moves in a certain constant amount of action, in the same manner as in the display with reduction. Therefore, it is impossible to allow the robot model to perform, for example, an accurate and fine adjusting action.
On the other hand, for example, a robot having three axes is assumed, in which, for example, only the first axis (X axis direction) is subjected to movement by using a pointing device such as a mouse. When the pointing device is operated by the human hand, the arm is moved rightward and leftward about a supporting point of the elbow. Therefore, the pointing device is moved along a line depicted as a circular arc. In such a situation, the second axis in the Y axis direction is also subjected to movement in addition to the first axis, and it is impossible to allow the robot model to perform the desired operation (operation to make movement only for the first axis). It is feared, for example, that such a situation may obstruct the work to confirm the off-line teaching performed for the robot model.
The present invention has been made taking the foregoing problems into consideration, an object of which is to provide an off-line teaching apparatus which makes it possible to inform, in real time, an operator of the fact that the system responds to an input of an operation command given by the operator, and which makes it possible to improve the operability of the off-line teaching.
Another object of the present invention is to provide an off-line teaching apparatus which makes it possible to process an inputted operation command in conformity with a display form (for example, with magnification, with reduction, as viewed from the front side, and as viewed from the back side) of a robot model, and which makes it possible to improve the operability of the off-line teaching.
Still another object of the present invention is to provide an off-line teaching apparatus which makes it possible to allow a robot model to act for only a specified axis by using a pointing device, and which makes it possible to improve the operability of the off-line teaching.
According to the present invention, there is provided an off-line teaching apparatus for allowing a robot model displayed on a monitor to act on a screen on the basis of an operation command supplied from an input device, wherein a sound for informing an input is generated at a point of time at which the input of the operation command from the input device is sensed.
According to the present invention, it is possible to inform, in real time, the operator of the fact that the system responds to the input of the operation command from the operator.
It is preferable for the off-line teaching apparatus constructed as described above that the sound for informing the input is generated at a point of time at which the operation command inputted at present is sensed during the action of the robot model effected on the basis of the operation command inputted previously.
When the processing load is light, the system quickly responds to the operation performed by the operator. Therefore, any sound generated in such a situation is merely a nuisance. For this reason, it is desirable that the sound is generated when the load is heavy, namely when the system fails to make quick response to the operation performed by the operator.
In a preferred embodiment, it is preferable that the sound is generated at a point of time at which the operation command from the input device is inputted into a buffer. Alternatively, it is preferable that the sound is generated at a point of time at which an interrupt indicating input of the operation command from the input device is generated. The generation of the sound at the foregoing points of time makes it possible to allow the operator to recognize that the system responds to the input given by the operator in real time.
In order to achieve the off-line teaching apparatus constructed as described above, the apparatus may further comprise an operation command-receiving means for receiving the operation command from the input device and storing the operation command in a buffer, an operation command-counting means for counting a number of operation commands stored in the buffer, and a sound-generating means for generating the sound upon receipt of the operation command by the operation command-receiving means when a counted value obtained by the operation command-counting means is not less than a predetermined number.
Accordingly, at first, the operation commands from the input device are successively received, and they are stored in the buffer, by the aid of the operation command-receiving means. The operation command-counting means is used to count the number of the operation commands stored in the buffer. The counting process is performed, for example, such that the value is updated by +1 every time when the operation command is stored in the buffer, while the value is updated by xe2x88x921 every time when the operation command is taken out of the buffer. Accordingly, it is possible to count the number of operation commands stored in the buffer. When the heavy load process is executed by using the system, the number of operation commands stored in the buffer is increased. Therefore, when the counted value obtained by the operation command-counting means is not less than the predetermined number, then it is judged that the heavy load process is executed, and the sound-generating means generates the sound when the operation command is received by the operation command-receiving means.
In another aspect, the present invention lies in an off-line teaching apparatus for allowing a robot model displayed on a monitor to act on a screen on the basis of an operation command supplied from an input device, wherein the operation command from the input device is interpreted depending on an operation point and a display form of the robot model to make a response.
According to the present invention, the inputted operation command can be processed depending on the operation point and the display form (for example, with magnification, with reduction, as viewed from the front side, and as viewed from the back side) of the robot model. Thus, it is possible to improve the operability of the off-line teaching.
In order to achieve the on-line teaching apparatus constructed as described above, the apparatus further comprises an operation command-receiving means for receiving the operation command from the input device, an action information-extracting means for deducing an operation point and a direction of action from the received operation command, a display form-reading means for reading a display form of the robot model from display orientation information on the robot model, an action attribute table registered with attributes of action corresponding to the display form and the operation point, and an action attribute-reading means for reading an attribute of action corresponding to the operation command from the action attribute table on the basis of an extracted operation point and read display form information, wherein the operation command is processed depending on the read attribute of action.
Accordingly, at first, the operation commands from the input device are successively received by the aid of the operation command-receiving means. The operation point and the direction of action are deduced from each of the received operation commands by the aid of the action information-extracting means. During this process, the information on the display form of the robot model is read from the information on the display orientation information of the robot model by the aid of the display form-reading means.
The attribute of action corresponding to the operation command is read from the action attribute table on the basis of the extracted operation point and the read display form information by the aid of the action attribute-reading means. The operation command is processed in accordance with the read attribute of action.
The action attribute table has a file structure in which the attribute of action can be accessed by using the operation point and the display form information as indexes.
For example, it is assumed that the operation point lies in the first axis, the information of xe2x80x9cnormal directionxe2x80x9d is registered for the display form information which represents the display as viewed from the front side, and the information of xe2x80x9copposite directionxe2x80x9d is registered for the display form information which represents the display as viewed from the back side. If the display of the robot model on the monitor is at the front side, and there is an input of the operation command indicating, for example, rightward movement with respect to the point of the first axis, then the robot model is moved in the normal direction, i.e., the robot model is moved rightward.
If the display of the robot model on the monitor is at the back side, and there is an input of the operation command indicating, for example, rightward movement with respect to the point of the first axis, then the robot model is moved in the opposite direction, i.e., the robot model is moved leftward. Similar action is also made for the rotational action.
In still another aspect, the present invention lies in an off-line teaching apparatus for allowing a robot model displayed on a monitor to act on a screen on the basis of an operation command supplied from an input device, wherein when a coordinate input device as one type of the input device is operated along a direction of movement of a certain joint of the robot model, if movement of the coordinate input device involves fluctuation in a degree of being included in a previously set insensitive zone in which a direction perpendicular to the direction of movement is its widthwise direction, then only movement based on the certain joint of the robot model is permitted.
According to the present invention, only the specified axis is allowed to make action for the robot model by using the coordinate input device. Thus, it is possible to improve the operability of the off-line teaching. In order to achieve the off-line teaching apparatus constructed as described above, the apparatus may further comprise a coordinate-reading means for reading inputted coordinate data from the coordinate input device with a predetermined time width, a joint-specifying means for specifying the joint of the robot model on the basis of coordinate data inputted at an initial stage, an insensitive zone-setting means for setting an extending direction and a width of the insensitive zone on the basis of the specified joint, a judging means for judging whether or not the inputted coordinate data is within a range of the preset insensitive zone, and a display-regulating means for permitting only movement of the joint specified by the joint-specifying means if a result of judgement obtained by the judging means is an affirmative judgement.
Accordingly, at first, the coordinate-reading means is used to read, with the predetermined time width, the inputted coordinate data from the coordinate input device. The joint of the robot model is specified by the aid of the joint-specifying means on the basis of the coordinate data inputted at the initial stage. Further, the insensitive zone-setting means is used to preset the extending direction and the width of the insensitive zone. The inputted coordinate data, which is successively read, is subjected to the judgement by the judging means to judge whether or not the inputted coordinate data is within the preset range of the insensitive zone. If it is judged that the inputted coordinate data is within the range of the insensitive zone, the display-regulating means is used to perform only the movement of the joint specified by the joint-specifying means.
If the inputted coordinate data exceeds the range of the insensitive zone, ordinary display is made corresponding to the coordinate data.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.